Melanotan II
Melanotan II (MT2), a synthetic alpha-MSH analogue
What is Melanotan II?
Melanotan II: Synthetic cyclic analogue of alpha-MSH that non-selectively activates melanocortin receptors (MC1R pigmentation, MC3R/MC4R sexual function and appetite). The sources cited here most often discuss it for: Tanning without UV, small trials; Erections in psychogenic ED; Appetite suppression, animal. Evidence label: Early human.
- Type
- Peptide
- Family
- Skin, Hair & Tan
- Evidence label
- Early human (3 of 5)
- Regulatory status
- Australia's TGA lists Melanotan II as a prescription-only medicine that is not approved as a tanning agent, with no approved products, and in August 2026 warned consumers after seized tanning nasal sprays proved inconsistently dosed.
- Goals discussed
- Skin & Glow, Libido & Sexual Health, Fat Loss & Metabolism
- Also called
- Barbie drug, vacation peptide, tan jab, tanning injections, MT2, Ac-Nle-α-MSH-NH2
- Last reviewed
- 2026-10-11
- Synthetic cyclic analogue of alpha-MSH that non-selectively activates melanocortin receptors (MC1R pigmentation, MC3R/MC4R sexual function and appetite); never FDA-approved, sold as unregulated 'tanning injection'; parent of bremelanotide (PT-141).12
Regulatory status Australia's TGA lists Melanotan II as a prescription-only medicine that is not approved as a tanning agent, with no approved products, and in August 2026 warned consumers after seized tanning nasal sprays proved inconsistently dosed. 3
Names as used in gyms, forums and gray-market listings. Reported, not endorsed; stacks have not been studied as combinations.
Within approximately 1 week of initiating melanotan, he noted rapid darkening of multiple preexisting nevi, describing that several lesions “turned black.
Single case report in a man who also used tanning beds and testosterone; causation by melanotan is not established.
What is Melanotan II researched for?
The three outcomes most discussed for Melanotan II in the sources below, as those sources report them. humanpeptides.fyi makes no claims of its own: a listed benefit can be unproven or can have failed in trials, and the label on each line says which.
Tanning without UV, small trials
What do researchers and users say about Melanotan II?
Published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism.
FDA safety assessment written during its review of a nomination to use Melanotan II in pharmacy compounding.
He told the doctors writing up his case that if he’d known this could happen, he never would have touched the drug.
Describing a published case of a 41-year-old man who developed a 22-hour priapism after buying melanotan over the counter.
What side effects of Melanotan II are reported?
- Nausea, flushing, vomiting, spontaneous erectionshuman trials, Reddit28
- Ischemic priapism requiring emergency treatmentcase reports1213
- Melanoma associated with usecase reports14
- Posterior reversible encephalopathy syndrome (a brain-swelling syndrome that can cause seizures) and sympathomimetic toxidrome described in published case reports.case report, cited by FDA10
- Rhabdomyolysis (muscle breakdown), kidney failure and renal infarction.case report15
- Pyoderma gangrenosum, ulcers that formed at the injection sites and took several months of treatment to heal.case report16
- Brown pigmentation of the gums and inner cheeks that can persist for months after stopping.case report17
- Products sold online can be inconsistently dosed; TGA testing of seized nasal sprays found the actual amount varied more than twofold between bottles with the same label.regulator lab testing3
What do peptide guides say about Melanotan II?
- PepEdHub PepEdHub explains that Melanotan II acts on melanocortin receptors MC1R through MC5R: MC1R drives tanning, MC3R and MC4R affect arousal and appetite, and it advises skin checks because moles can darken. 18
- Seek Peptides Seek Peptides lists sunless tanning as the main use and describes appetite suppression and libido effects as secondary effects some users notice; none of these uses is approved. 19
- NCBI PMC A 2020 case review calls it the Barbie drug, notes it is mostly bought illegally online, and links it to rhabdomyolysis, kidney failure and a probable case of renal infarction. 15
- NCBI PMC In a 2026 case report, brown patches on the gums and inner cheeks appeared during use; cheek pigmentation faded within a month of stopping, but gum discoloration persisted at three months. 17
- Skin Cancer Foundation The Skin Cancer Foundation notes Melanotan II is not FDA-approved for any use, and warns that rapid mole changes after use can make skin cancer harder to detect. 20
What does the research say, system by system?
How strong is the evidence for Melanotan II?
Small early human trials (tanning, ED) + case reports and anecdotes; unapproved, unregulated, with notable safety signals
Small, short, old, unblinded or single-group human studies. How tiers work
Questions about Melanotan II
What is Melanotan II?
Synthetic cyclic analogue of alpha-MSH that non-selectively activates melanocortin receptors (MC1R pigmentation, MC3R/MC4R sexual function and appetite).
Is Melanotan II FDA-approved?
Australia's TGA lists Melanotan II as a prescription-only medicine that is not approved as a tanning agent, with no approved products, and in August 2026 warned consumers after seized tanning nasal sprays proved inconsistently dosed.
What is Melanotan II researched for?
The sources cited on this page most often discuss three outcomes: Tanning without UV, small trials; Erections in psychogenic ED; Appetite suppression, animal. Each line above shows what the source reports and how strong that evidence is.
What side effects of Melanotan II are reported?
Reported in the cited sources: Nausea, flushing, vomiting, spontaneous erections; Ischemic priapism requiring emergency treatment; Melanoma associated with use. The list is not complete, and few listed risks does not mean a compound is safe.
How strong is the evidence for Melanotan II?
Evidence label: Early human. Small early human trials (tanning, ED) + case reports and anecdotes; unapproved, unregulated, with notable safety signals.
What else is Melanotan II called?
Names used for it include Barbie drug, vacation peptide, tan jab, tanning injections, MT2, Ac-Nle-α-MSH-NH2.
Does humanpeptides.fyi recommend Melanotan II?
No. humanpeptides.fyi makes no claims and no recommendations of its own. It summarizes and links to what others have published and posted. Nothing here is medical advice; talk to a licensed clinician.